1. Field of the Invention
The invention relates to motor vehicle doors such as conventional motor vehicle side doors, sliding doors, rear doors which can move to the top or side, and rear hatches, etc. More specifically, the invention relates to such doors having a door frame and an outside door panel which can be mounted on the door frame.
2. Description of the Related Art
In the following specification, the term motor vehicle door is used to represent all the various types of doors used on motor vehicles such as side doors, sliding doors, rear doors and rear hatches. In motor vehicle doors, there is generally provided a door frame which is made as torsionally rigid as possible. The door frame is usually made of a metal or metal sections which may, in the prefered embodiment, be made from aluminum sections. The paneling of the door frame is accomplished by attaching an outside door panel to the door frame. The outside door panel generally made from a thin metal sheet or a molded plastic. The motor vehicle doors also include a corresponding inside door panel in addition to an inside door covering or alternatively, an integrated inside door panel/inside door covering.
An important objective in designing and constructing a motor vehicle door is to provide a simple structure in the area of the motor vehicle door that will allow prompt and simple repair of any door component. Examples of this can be found in the published German patent applications DE 195 14 963 A1 and DE 195 14 964 A1.
The DE 195 14 963 A1 application discloses a motor vehicle door including a door frame and an outside door panel which is detachably mounted on the door frame. In this application, the door frame which has a retaining groove on an edge which runs roughly transversely to two other sides of the door includes a transversely running catch groove assigned to an edge of the outside door panel which is the upper edge when the outside door panel is in the installed position. The outside door panel includes a catch rail on a corresponding edge which is assigned to and fits into the catch groove. On the opposite lower edge, the outside door panel has a retaining groove formed by a U-shaped bend. This groove interacts with a retaining rail which is located on the lower edge of the inside door panel which is drawn forward into an area of the outside door panel. For mounting purposes the outside door panel is shifted from the bottom to the top on the door frame such that the retaining rail on the inside door panel fits into the retaining groove on the outside door panel and the catch rail on the outside door panel fits into the catch groove on the door frame.
Therefore, according to this application, the motor vehicle door is comprised of the door frame, outside door panel, and inside door panel. Furthermore, the outside door panel is directly connected to the inside door panel, and consequently, the outside door panel can be mounted only in conjunction with the inside door panel.
When using a non-reinforced plastic with high coefficient of thermal expansion for the outside door panel, the above explained prior art motor vehicle door requires considerable gap dimensions in the door area because the outside door panel lengthens considerably (several millimeters) in the longitudinal direction (in the installed position) when the outside door panel is heated by high ambient temperature conditions. Of course, because the door frame is made of a metal which has a lower coefficient of expansion than the plastic, the door frame does not lengthen to the same extent as the plastic outside door panel.
In the motor vehicle door disclosed in German application DE 690 00 874 T2, the outside door panel is attached to the door frame by first pushing the panel vertically from the bottom to the top relative to the door frame, and then, by pushing the panel into the end position horizontally from the back to the front. When shifted horizontally, forward pointing clamps located on the upper edge and the front edge of the outside door panel are inserted into the corresponding openings on the door frame, thereby hooking in the outside door panel. In addition, this application also discloses grooves formed on the bottom edge and rear edge of the outside door panel which are inserted into the assigned edges of the door frame.
Thus, the above applications disclose various feasible methods for attaching an outside door panel to a door frame. A disadvantage with these methods is that, because of the recesses in the door frame, metal-cutting or similar metal processing on the door frame is necessary. Furthermore, these prior art designs do not effectively address the problem of high thermal elongation of the outside door panel when these panels are heated. As a result, the gap dimensions required to allow this expansion remains large and unchanged from other designs known in the art.